1. Field of Invention
This invention generally relates to wireless communication systems and, in particular, to short message service (SMS) communications in wireless communication systems.
2. Discussion of Related Art
The tremendous growth of the Internet in recent years has fueled the need to provide wireless devices such as mobile telephones, personal digital assistants (PDAs) and the like with access to information and services available on the Internet. However, providing wireless devices with access to the Internet is complicated by the fact that various different carrier networks with different wireless network characteristics are used domestically and world wide to communicate with the wireless devices. Examples of wireless networks include Cellular Digital Packet Data (CDPD), Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA) and Time Division Multiple Access (TDMA) to name a few, and each of these wireless networks has different data transfer characteristics such as latency, bandwidth, protocols and connection methods. As examples, protocols can be Internet Protocol (IP), Short Message System (SMS) and Unstructured Supplementary Service Data (USSD), and connection methods can include packet switched or circuit switched. A carrier transport ID indicates the protocol used by the network, such as User Datagram Protocol (UDP), Short Message Peer-to-peer Protocol (SMPP), or Wireless Datagram Protocol (WDP).
Wireless communications are used for voice and data communications. In the case of wireless data communications, one type of service that can be provided by wireless networks is SMS. Short Message Server Centers (SMSCs) associated with the wireless networks provide the SMS service. SMS gives subscribers the ability to receive a relatively small amount of information over the wireless networks. The information provided through SMS is generally referred to as messages and can, for example, include text messages, electronic mail (email), voice mail, message alerts and pages from pagers. SMS tends to be a more cost effective means for the transmission of small amounts of data because SMS uses considerably less bandwidth than a typical wireless phone call or wideband network connection. SMS channel usage is also typically charged to subscribers at a fixed cost per month so its bandwidth, although limited, tends to be relatively inexpensive for subscribers.
One-way-SMS represents a narrowband channel that can carry data in primarily one direction, with acknowledgements going in the opposite direction. Two-way SMS allows bi-directional communications over SMS using a channel with a relatively low bandwidth, which is slightly greater in capacity than that provided by one-way SMS.
An SMS communications system can be thought of as a client-server type of system where a client device makes a request, and upon reception, a server device acknowledges whether or not the request was received in tact. In the case of SMS, the acknowledgements represent a success report if the request was successfully received or an error report if the request was not successfully received. For example, when a mobile device sends a message to an SMSC, the SMSC returns a report to the mobile device to either confirm receipt of the message or to notify of error in the delivery of the message. If the message is received successfully, the SMSC stores and forwards the message to an entity capable of receiving SMS messages. This forwarded message contains the address of the originating entity. In a similar fashion, when the SMSC delivers a message to a mobile device, the mobile device returns a report to the SMSC to either confirm receipt of the message or to notify of error in the delivery of the message.
These reports, which provide an indication of a successful or failed delivery process, are referred to as SMS acknowledgement messages. SMS acknowledgement messages are comprised of a plurality of pre-defined functional fields. Examples of successful acknowledgement reports include the Submit Success Report (SSR) and the Delivery Success Report (DSR). These multi-field success acknowledgement reports have a well-defined structure, which includes user data fields. These user data fields are generally not utilized at present and therefore they represent wasted bandwidth to the network. The failed reception acknowledgement error reports are referred to as error reports and do not have user data fields. SMS is further described in Global System for Mobile Communications (GSM) 03.40, versions 5.6.1, European Telecommunications Standards Institute (ETS) (ETS 300 901), January 1998, which is hereby incorporated by reference.
Thus, given the growth of wireless services and the fixed cost pricing of SMS channels, there exists a need for more efficient utilization of SMS systems to accommodate an increase in subscribers and their usage.
Broadly speaking, the present invention relates to techniques that enable wireless client devices to more efficiently utilize the available transmission bandwidth in a wireless network. In one embodiment, the invention operates to include or incorporate return information (data) in an acknowledgement message after an incoming message has been successfully received from a sender.
The invention can be implemented in numerous ways, including as a method, an apparatus, and a computer readable medium. Several embodiments of the invention are discussed below.
As a method for sending messages between a client device and a server device through a narrowband channel of a wireless data network, one embodiment of the invention includes the acts of: receiving a message at the client device, the message being sent from the server device to the client device through the narrowband channel of the wireless data network; preparing an acknowledgement message to be returned to the server device, the acknowledgement message including at least a portion of another message destined for the server device; and sending the acknowledgement message to the server device. As an example, the client device can be a personal digital assistant, a mobile telephone device, or a pager.
As a method of transmitting message packets from an initiating unit to a receiving unit over a wireless data network using a Short Message Service Center, one embodiment of the invention includes the acts of: maintaining, at the receiving unit, a message queue of messages awaiting delivery; receiving, at the receiving device, a message from the initiating unit over the wireless communications using the Short Message Service Center; determining whether the received message is valid; determining whether the message queue contains a deferred message awaiting delivery to the initiating unit; generating an acknowledgement message that incorporates at least a portion of the deferred message awaiting delivery to the initiating unit; and forwarding the acknowledgement message to the wireless client device over the wireless communications using the Short Message Service Center.
As a computer readable medium including computer program code for sending messages between a client device and a server device through a channel of a wireless data network, one embodiment of the invention includes: computer program code for receiving a message at the client device, the message being sent from the server device to the client device through the channel of the wireless data network; computer program code for preparing an acknowledgement message to be returned to the server device, the acknowledgement message including data destined for the server device; and computer program code for sending the acknowledgement message to the server device.
As a computer readable medium including computer program code for of transmitting message packets from an initiating unit to a receiving unit over a wireless data network using a Short Message Service Center, one embodiment of the invention include: computer program code for maintaining, at the receiving unit, a message queue of messages awaiting delivery; computer program code for receiving, at the receiving device, a message from the initiating unit over the wireless communications using the Short Message Service Center; computer program code for determining whether the received message is valid; computer program code for determining whether the message queue contains a deferred message awaiting delivery to the initiating unit; computer program code for generating an acknowledgement message that incorporates at least a portion of the deferred message awaiting delivery to the initiating unit; and computer program code for forwarding the acknowledgement message to the wireless client device over the wireless communications using the Short Message Service Center.
As an apparatus for sending and receiving messages over a wireless data network, one embodiment of the invention includes: an outgoing data queue that stores data to be sent over the wireless data network; a message manager, the message manager manages (i) the reception of incoming messages from senders over the wireless data network and (ii) the generation of outgoing messages to be sent over the wireless data network; a storage medium that stores the incoming messages; and a processing module operatively connected to said message manager and said storage medium, said processing module interacts with said storage medium and said message manager to request, send and receive data over the wireless data network. The outgoing messages generated by said message manager include acknowledgement messages that acknowledge the receipt of at least some of the incoming messages. Depending on availability of data in said outgoing data queue, the acknowledgement messages generated by said message manager include data from said outgoing data queue destined for the respective senders of the incoming messages being acknowledged.
The advantages of the invention are numerous. Different embodiments or implementations may yield one or more of the following advantages. One advantage of the invention is that wireless devices to more efficiently utilize the available transmission bandwidth of a narrowband channel (e.g., SMS channel) in a wireless network. Another advantage of the invention is that it facilitates cost-effective use of a narrowband channel (e.g., SMS channel) in a wireless network. Still another advantage of the invention is that non-time critical messages can be sent over a wireless network in efficient, cost-effective way.